The subject matter disclosed herein relates to the art of electric switchgear and, more particularly, to switchgear including a withdrawable switchgear unit having a blocking mechanism.
In general, a switchgear serves as an interface between an electrical supply and an electrical load. The switchgear is arranged in an enclosure that includes a line or busbar portion and a load or circuit breaker portion. The busbar portion includes one or more busbars that are connected to the electrical supply. The circuit breaker portion includes one or more circuit breakers that are electrically connected to the one or more busbars and an electrical load. The circuit breaker is configured to interrupt a flow of current from the one or more busbars to the electrical load in the event of an over-current condition, short circuit condition and/or an over/under voltage condition.
In some cases, the one or more circuit breakers are mounted to a withdrawable unit. A withdrawable unit may be shifted relative to a shelf in the switchgear. The withdrawable unit may be shifted between a service position, a test position, and a disconnected position. Each position establishes a corresponding configuration, e.g., (service configuration, a testing configuration, and/or a disconnected configuration, for the one or more circuit breakers.